Chapter 8 introduces the principles of experimental methods to determine various transport properties in multiphase flows. Typical properties include geometric characteristics of dispersed phase, phase volume fractions, mass fluxes or flow rates, velocities, and electrostatic charges. Specifically, the particle size and morphology are measured via the optical image, sieving, sedimentation, cascade impaction, and laser-scattering method. The volume fraction can be determined by the beam-attenuation, permittivity, and tomography principles. The mass flow rate can be determined from the isokinetic sampling and ball probe method. Phase velocities can be measured using the cross-correlation, LDV, and PIV methods. The electrostatic charge is typically measured by Faraday cup and induction probe. The introduction is focused on the basic mechanisms and applicability of the measurement techniques. The chapter also discusses the data analysis methods describing the particle size distribution from overlapped size sampling, such as the deconvolution method.It is also important to identify the equivalent diameter of nonspherical particles that a size measurement reveals.